Immutably rename object keys

Return a copy with keys renamed through a mapping.

JavaScript Version 1.0.0 · MIT · .md

function renameKeys({ keysMap, object }) { return Object.fromEntries(Object.entries(object).map(([key, value]) => [keysMap[key] || key, value])); }

Try in the local lab Download function

Input & expected output

Input

{
  "keysMap": {
    "idempotency_key": "idempotencyKey"
  },
  "object": {
    "to": "[email protected]",
    "idempotency_key": "order-confirmation:8812:1"
  }
}

Expected output

{
  "to": "[email protected]",
  "idempotencyKey": "order-confirmation:8812:1"
}

The edge case

Input

{
  "keysMap": {},
  "object": {}
}

Expected output

{}

Know the limits

Object.fromEntries replaces the original reduce with spread, which copied the accumulator on every key.
If two keys map to the same name, the later one wins.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Source & maintenance

Uses Object.fromEntries instead of spreading the accumulator for every key. Original MDX retained as inert source evidence.

Maintained by Oveyon. Source commit: 14b481cf60df. Read the license.

Local fixture scope · Node.js 22.23.2 · reviewed October 28, 2026. No external service is required.

Keep exploring

Pick properties from an object — Build a new object with only the requested own properties.
Omit properties from an object — Keep the own enumerable fields that are not in a supplied list.
Create an object from pairs of key and value — Turn [key, value] pairs into a plain object with Object.fromEntries.